Intratherapeutic Biokinetic Measurements, Dosimetry Parameters Estimate, and Monitoring Treatment Efficacy using Cerenkov Luminescence Imaging in Preclinical Radionuclide Therapy.

In recent years, there has been an increasing amount of interest in non-invasive Cerenkov Luminescence Imaging (CLI) of in vivo radionuclide distribution in small animals, a method proven as a high-throughput modality for confirmation of tracer uptake. 11B6 is an IgG1 monoclonal antibody that is specific for free human kallikrein-related peptidase 2 (hK2) an antigen abundant in malignant prostatic tissue. Free hK2 was targeted in prostate cancer xenografts using (177)Lu-labeled 11B6 in either murine or humanized forms for radionuclide therapy (RNT). In this setting, CLI was investigated as a tool for providing parameters of dosimetric importance during RNT. First, longitudinal imaging of biokinetics using CLI and single-photon emission computed tomography (SPECT) was compared. Second, the CLI signal was correlated to quantitative ex vivo tumor activity measurements. Finally, CLI was used to monitor the radionuclide treatment and it was found that the integrated CLI radiance correlated well with subject-specific tumor volume reduction.